Apparatus for feeding fuel to internal combustion engines



VF. EGERSDORFER ET AL Sept. 19, 1939.

APPARATUS. FOR FEEDING FUEL TO INTERNAL COMBUSTION ENGINES 2 Sheets-Shet 1 Filed Aug. 31, 1937 fifi'omey Sept. 19, 1939.

F. EGERsbQRFER ET AL 2,173,578

APPARATUS FOR FEEDING FUEL TO INTERNAL COMBUSTION ENGINES Filed Aug. 31, 1937 2 Sheets-She et' 2 FROM/WE SUPPLY 1/25 I 7! M 20 I 33 Z? )L V A27 f "I 3U I v 3 I I M 7 2 7 I 77 T 5 Jaw/250m:

Patented Sept. 19,1939 l q A v U ITED; j STATES mm- OF s u g Applcation AIM-3i, 1,37, Serial No. 161324 6m! m sts-1935 r Our invention relates to improvements in apgearwhcels-are fixed-to the shaftsandthe sleeves paratus for feeding fuel to internal combusion eniniwhich the shafts are rotatable in bushings S es, and more particularly in apparatus for fixed to'the Thereby the manufacture of feeding fuel from the fuel tank or-tanksto the e r mvs w h a small clearance is made g carbureter or injection pump of the engine. cult; While the apparatus is valuable in connection According to the invention pumps of the type with internal combustion engines of any type, it referred to are used in which the gear wheels and is particularly useful in connection with air craft; t e bu in s have e l diameters Pumps Qur invention consists in providing two pumps this type are knowm But as distinguished from 10 having separate suction conduits for supplying such known pumps the gear wheels and the the fuel from the m or. tanks and .a -common bushings are mounted so as to be floating in axial pressure conduit for supplying the said. fuel to direction and so that the gear wheels and the the engine. Thus both pumps feed the fuel indebushings may set themselves into the positions 7 pendently of each other, fuel being supplied also. which bestanswerthe requirementsof service. 18 when one of the said suction conduits is-inlured For the purpose ofexplaining' the invention an or one of the tanks is emptied, or if one of the example embodying thesame has been shown suction conduits does not receive fuel from the in the new drawing in which the tank by'reason of the tank being inclined.. Each same reference characters have been used in allpump is constructed for feeding an amount of fuel the views to indicate-corresponding parts. I 20 which is in excess of the highest demand of the In said drawings: a a

engine, and a regulating device is :provided for .1 is a sectional elevation of the pump returning the excess of fuel from thepressure takenontheline l-l of-Iig. 4,

conduit to the suction conduits, the said fuel berig. in a detailsectional view taken on the ing returned into both suction conduits, so that line 2-401 Fig. 1, in any case both pumps have a supply of iuel, even Fig. 3 is a plan view partly in section taken on 25 if only one of them receives fuel from its-tank. thelinej-l of Fig. 1, and v This is important to Fig. 4 is a sectional view taken'onthe line 4+4 Dump running idleis prevented. I of Pig. '1; V

For regulating the black jlow of the fuel-from: Inthe-exampleshown i the fi res i'eed pump the pressure conduit to'the suctionconduits; oi'cfthe type comprising ''pairs of interengaging spring pressed regulating piston is provided in a gear wheels are provided, and the said pairs of regulating cylinder which is connected at one end' gear wheels 2, 8 and 3. l are mounted within the of the piston with the pressure conduit,.and of acylindrical portion which has return conduits or slots for the fuel and heads; The cylinder chamber isdouble provided in the cylindrical wall at diametrically and takes the form of m parallel and overlap- 35 opposite sides of thecyllnder, so that the reguping cylindrical spaces, as will be perceived on lating piston is held in equilibrium within the considering particularly'fig. of the drawings. cylinder and is not pressed to the wall thereof The suction conduitsllgnd ll ofeach pump areby the vacuum within one of the suction-conduits; connected by means of pipes to the fuel tank or 49 The regulating apparatus may be used in cbnwhile the pressure conduits are connected 40 nection with pumps of any type; But it isprethrough a e H to a common tubular porferred to provide-pumps of the type in which the tion it of the casing o! 'the pump, and the said fuel is supplied by means of a pair of .interen'gagtubular portion is connected through a pressure ing gear wheels rotating in a cylindrical casing pipe with the carbureter or fuel injection pump and connected at one side of the pair of gear of the internal combustion engine. The gear 45 wheels with the suction conduit and at its opposite wheels 2 and I are mounted on a shaft I side with a pressure conduit. Preferably the and they are connected therewith by means of said pumps are combined within one casing, corkeys ll permitting axial play 0! the gear wheels responding gear wheels of the said pairs being L on the shaft. The said drivingshaft ismounted mounted respectively on the same axis. In such in bushings 4, Land i, the bushing} being 10- 50 pumps for feeding gasoline the clearance between cated between the gear wheels 2 and ,3. The out- V thegearwheelsandtheadlacentsleevesandwalls wardly projecting end of the driving shaft'is of the casing must'be reduced as far as possible; passed through a stuiiing land I. The-gear inordertoinsureasumcientvacuumandhigh wheelslandiarelooselymountedonashaft emciency. Inpumpssuchasarenowinuoethe l0. Inathesaidgearwheelsare mounted in bushings ll, i2, and I3. In both cases the gear wheels are longitudinally shiftable on the shaft III. In other modifications only the gear wheels and the bushings 4 and I2, or all the bush-- ings 5, 6, I l, and i3 and the gear wheels are axially shiftable. The end faces of the bushings 5 and 6 are flush with the end faces of the cylindrical casing 3i, and'accordingly the heads 32 have plane inner faces.

The diameters of the bushings and gear wheels are alike. One set of bushings,'viz., the bush ings Ii, l2, and i3 are perfectly cylindrical, while the corresponding bushings 4, 5, and 6 are formed with cut-out portions accommodating the bushings ii, [2, and i3. The bushings ll, i2, and i3 must be fixed as against rotary movement, while rotary movement of the bushings 4, 5, and 6 is prevented by the cut-out portions being engaged by the bushings H, 12, and I3, so that additional means for preventing rotary movement of the bushings 4, 5, and 6 may be dispensed with. As appears from Figs. 1 and 2 rotary movement of the bushing I2 is prevented by means of a screw i4 engaging in a slot i5 made in the bushing and permitting axial displacement thereof. Similar locking means are provided in connection with the bushings ii and i3. The bushings form within the cylindrical spaces chambers within; which the gear-wheels rotate.

The excess of fuel fed by the pump or pumps is returned to both suction conduits through passages 2i and 22, and the back flow is controlled by means of a regulating device shown in Figs. 3 and 4. The tubular portion l6 providing the common pressure conduit of both pumps is connected through a branch conduit 11' with a regulating cylinder l8 in which a regulating plunger i9 is located, the said plunger being acted upon by a spring 20' tending to shift the same to the right in Fig. 4 and into position for closing the conduits 2| and 22. The tension of the spring may be regulated by a screw 33. The bores through which the conduits 2| and 22 are connected withthe cylinder 18 are located at diametrically opposite parts of the said cylinder. At the rear or left hand side of the piston I 9 the cylinder [8 is connected through a passage 25 either with the -outer air or, where. compressed air is supplied to the engine, with the said supply of compressed air. Thus where compressed air is supplied to the engine the pressure of the fuel is always increased in the same degree as the pressure of the air supplied by the compressor to the engine. In

a modification the pressure of the said air is. transmitted to the piston through the intermediary or an elastic diaphragm.

We claim:

1. An apparatus for feeding fuel to internal combustion engines, comprising two pumpshaving their suction passages adapted to be connected to the supply of fuel and having a common pressure conduit for the supply of fuel to the internal combustion engine, and a regulating device con- 1 nected with said pressure conduit and with both suction passages and constructed for returning excess of fuel to both suction passages.

2. An apparatus as claimed in claim 1, in which the said regulating device comprises a cylinder 1 having a controlling member movably mounted therein, the said cylinder being connected at one side of the controlling member with the said pressure passage, the cylinder being provided in its walls with diametrically opposite bores com- 2 municating severally with the said suction passages, the said controlling member being movable in response to pressure in said pressure passage from a position of closure with respect to said bores. I 2

3. An apparatus as claimed in claim 1, in which the regulating device comprises a cylinder having a plunger reciprocating therein, said cylinder being connected at one side with said pressure conduit and with said suction passages, the ports 3 to shift the same in opposition to the pressure acta ing thereon and into position for closing said ports.

4. An apparatus for feeding fuel to internal" combustion engines, comprising two pumps having their suction passages adapted to be con- 4 nected to the supply of fuel and having a common pressure conduit for conveying fuel to the engine, and a regulating device including a plunger adapted to be subjected on one side to the pressure in the said pressure conduit and on the other 4 side to the pressure of anair supply, and return passages from the pressure conduit to the suction passages of the two pumps, said plunger normally closing said passages and movable from its position-of closure in response to excess pressure in 5 the pressure conduit.

FRANZ WUCHERER.

'mrrz EqERsnoRrER. 

